The objective of the Core Endocrine Laboratory is to provide an infrastructure for the measurement of hormones in body fluids for the three projects in this application. Dr. Laurence Demers, a renowned endocrinologist at Penn State University, will set up this facility at Meharry Medical College. In order to accomplish this objective, the following goals will be met: 1. Assemble protocols for different hormone assays in this application. 2. Validate each assays system to make sure that the highest sensitivity per assay is achieved and the intra- and inter-assay coefficients of variation (C.V.) are within acceptable limits (intra-assay C.V., 10% or less; inter-assay C.V., 20% or less). 3. Train research and graduate/medical students in the art of radioimmunoassay. 4. Maintain equipment in the Core Endocrine facility in a functional condition by providing service contracts for major equipment.